The overall objective of the project is to isolate from plants of the family Compositae new compounds which may have antitumor, schistosomicidal or other biological properties. Many of the plants to be studied are used as medicinal plants in the countries of their origin. Emphasis will be placed on sesquiterpene lactones which in addition to their potential activity are also useful for the clarification of evolutionary relationships in this important plant family. The applicability of a newly-discovered bromimetic type furan synthesis for the preparation of furanoterpenes and the lactones derived from them will also be explored.